Power transmission



Dec. 16, 1930.

J. c. sMooT 1,785,051

POWER 'IRANSMI S S I ON Filed July 20, 1927 2 Sheets-Sheet l f6/7700i f Mw by Jiallb/ Many@ afname 7?@ an of,

Dec. 16, 1930. J. c. sMooT POWER TRANSMISSION Filed July 20, 1927 2 Sheets-Sheet 2 d; 0.607002? f/Vow by :Ila/ffb/ cange of name JT@ Pad/7oz 13;

Patented Dec. `1de, 1930 PATENT {oFFicE :rnssn c. sMoo'r, or LincoLniroN, NORTH oaaoiiiva, Now BY JUDICIAL ,CHANGE or `ivaivin :mss COVINGTON aanivoa Y Y Appucanbn' med v:iuiyleaY 1927. serial No. 207,225.Y

ence to the application of power to twoperfectly aligned shafts, Jforming single shafts turning upon an axis which is perpendicular to the aXis of the iirst named shaifaand has more `precise reference to the application of powervto the two axle shaitsV of the standard automobile, or the like,v rear axle `and dilierential assembly'froin'a propeller or'drive shaft. Y

The object is tov provide means 'whereby the power `and energyo the autoinobileengine may be applied to Athe axle shafts and 'rear' wheels in two ldifferent-r'atios of fg'ear reduction, which ratios maybe arbitrarily selected and Achanged by means loffa lever operated by the driver, and both of which shall be equally silent and free'trom'vibration,to thereby enable the car tofbe runat' a slower engine Vspeed .under ordinary Iuse "to produce a reduction in fuel* 'coiisuniption, and to provide areduced gear ratio which will deliver more power to the rear wheels whenever such additional power is actually needed.`

In the standard automobile, power isde- `livered to the rear axles and wheels through the medium of `a transmission gear mechanism andpropeller shaft.. VGrear reduction is accomplished through the employment of a counter-shaft and system of gears in the transmission gear housing. This device usually provides two or three gear ratios for the forward vmotion of the automobile, these being' of a greater reduction in gear ratio than the direct drive, orv so-called high gear7 power transmission directly from the engine to the ring gear `on the" differential.

The more powerful gear ratios are provided to-enable the vautomobile to travel over hills and other constructions, which require p more power than do ordinary roads of travel.

- Theemployment ofthe counter-'shaft in the transmission gear box orVI housing, results-iii a grinding and undesirable noise which` is objectionable and which often compels the driver to use avmucli more powerful gear ra- Atio than the conditions require, and natural- .-ly this consumes more fuel than would be necessary witha slightly higlier'gear ratio;

The objectionable feature `of employing the countershaft and lgears to overcome more diflicult progress has resulted in the manufacture of the standardautomobile with the direct or high gear drive bearing such a low ratio to the axle shafts, aswill permit the standard automobile to travel over a large variety of vinclines withoutA employing the countershaft vand gears in the conventional transmission mechanism: Thus, while tray- `eling lupon a -level road, the standard automobile engine is revolving at'ahigher rate of speedand delivering more power with a consequent n greaterV fuel consumption than is c necessary.

l The vpresent invention overcomesthese difficulties by providing two different gear ratios which are both direct `drives `from the' engine to the y differential assembly,v and .which are independent of, and which may be operated `without the employment of, the

standard gear reduction-devicesin the'A usual transmission housing.

The invention makes possibletwo gear ratios,"one slightly higher than Vthe standard direct drive for ordinary level roadways, and a seconddirect driveislightly lower than the ordinary directdrive of standard automobiles. Both ofthese .will be noiselessand freeY fromwibration caused by` the employment of the transmission gear box reduction gears. .l

The-inventionenables a car to travel over a great variety'ot roadways and inclinations of roadwayswith the power more accurately apportioned to the needs of the car than is possible with the standard .transmission gear reduction devices.

The invention provides a lower gear ratio for diilicult passage which is a directl drive and which is free from vibration and noise, as is inevitable when the standard transmission devices are employed for/the same purpose.

The invention provides a higher gear ratio for level roadways than is practical inthe ice standard automobile where the single direct drive must be sufficiently powerful to enable the automobile to operate over` difficult and hilly conditions of roads.

The invention effects a saving in fuel consumption by providing a higher direct drive gear ratio and consequent lower engine speeds for. level roadways. Y

The construction for accomplishing this dual direct drive, and for effecting the alleged advantages, will become more readily apparent from the following description and the accompanying drawings.

Tn the drawings Figure 1 is a fragmentarv elevational and sectional view showing the complete improved structure, as constructed in accord ance with the present invention, the parts of the drive being in neutral position.

Figure 2 is a similar view showing the elements of the structure arranged in what may be referred to as the third speed drive, wherein the ratio is approximately five to one, that is five revolutions of the propeller shaft to one revolution of the axle shafts.

Figure 3 is also a view like Figure 2, showing the fourth speed drive position, wherein the ratio is approximately three to one.

Referring to the drawings now, by, reference characters, it will be observed that the reference character 4 represents generally an automobile engine propeller shaft, which is here shown with a reduced end formed into a propelling clutch member, designa-ted by the character 5. As is usual, the propeller shaft is housed in an appropriate protective casing of the design represented. Mounted for longitudinal shifting motion within the large bell-like end of the casing 6 is a sliding sleeve or coupling 7 operated by the control rod 8. Incidentally, the control rod leads to an appropriate manipulating lever within reach of the driver. This sleeve 7 is provided with internal clutch teeth in constant mesh with the teeth or splines of the clutch member 5.

Also at the rear end, the said sleeve is pro vided withl an external clutch member 8 and an internal clutch member 9, these being of the configuration disclosed.

The internal clutch member 9 is adapted to mesh with an external clutch member 1() which is formed upon the forward end, and is au integral part, of a solid driven shaft 11, the rear Vend of which is formed into a bevel pinion gear 13 which is in constant mesh with a comparatively small ring gear 14 fastened upon a rotary disk 15 which has driving connecting with an ordinary differential designated generally by the reference character 16. The shaft 11 is journaled for rotation in appropriate bearings 12 and 21. The rear bearing 21 is based in a projection of the bell-housing of the diierential assembly, and is rigidly attached to the didierential assembly.

Surrounding the solid shaft 11 is a tubular shaft 17 having an internal annular clutch member 18 adapted to mesh with the clutch member 8. This tubular shaft 17 carries, at its rear end, a relatively small pinion gear 19 which is in constant mesh with a proportionately large ring gear 20, also carried by the disk 15. The tubular shaft 17 is sup ported at its forward end by the bearing 23. The rear end is supported by a bearing 24 built within the large pinion gear 18, which pinion gear is supported as aforementioned by the bearing 21 based upon a projection of the bell-housing for the differential. A projection'of the tubular.v shaft 17 beyond the small pinion gear 19 fits into the inner cone of the aforementioned bearing 24, whereby the said bearing 24 supports the rear end of the shaft 17 in the same axis of rotation as the solid shaft 11. The shafts 11 and 17 rotate upon the same aXis and are supported in bearings one upon the other, the system of bearings being based at the circumference at the forward end and at the center at the rear end. The built-in bearing 24 is disclosed in Figure 2. i

Sufficient clearanceis maintained between the inner wall of the tubular shaft 17 and the periphery of the solidshaft 11 as to permit the two shafts to rotate free of each other.

The propeller shaft 4 is supported at its extreme rear end by a small radial bearing of suitable size which is carried upon a projection of the solid shaft 11. This bearing is designated by the character 22 in the drawings.

As before stated, the parts shown in Figure 1 are in a relationship known as neutral. lt is obvious, however, that by shifting the rod 8, the sliding sleeve clutch member 7 may be moved from neutral into the position shown inFigure 2, which is known as the third speed drivel. In this position, the clutch member 8 is brought into mesh with the complemental clutch member 18, thus setting the pinion 19 into rotation for co-operation with the large ring gear 20.

In this arrangement, the sliding sleeve gear is in suspended position. However, it may be retracted as shown in Figure 3, whereupon, the internal clutch member 9 will be brought into mesh with the clutch member 10 to drive the solid or inner shaft 11. turn, drives the large pinion 13, which is in mesh with the smaller ring gear 14, thus producing a higher rate of speed at the axle shafts with the same rate of speed at the propeller shaft.

From the foregoing, it will be -seen thatV I have evolved and produced an improved power transmission drive to the differential assembly of any automobile, embracing a conventional differential proper, but using This in 4 .has e,

two pinion gears of different sizesengaging with two gear rings of different diameters mounted upon a driving disk constituting a part of the revised differential. .The two pinion shafts, both the inner solid shaft and the outer tubular shaft, rotate upon the same aXis and are free of each other. The rear end of the conventional propeller shaft is splined and a sliding sleeve fits over this end and transmits power to either of the two pinion gears, according to the position of the shifting rod.

The tubular shaft drives the disk l5 at an approximate rate of five revolutions of the i propeller shaft to one revolution of the disk; f

while the solid shaft 11 drives at the approXimate ratio of three to one. y 5

As before indicated, the objectA of the device is to secure two speeds to the rear .axles that are direct drives that do not employ the counter-shaftgears in the transmission, and which provide a means of reducing engine speed and fuel consumption through a higher ratio where excess power is not needed and another speed which is a lower gear ratio with more pulling force which is equally a part of the conventional high gear in automobiles.

The two gear ratios, may of course, be arbitrarilyfixed at any combination desired. The gist of the inventionis in the use of two pinions and complemental solid and tubular Y shafts, wherein these shafts haveindependent operation and may be selectively coupled to the propeller shaft; the propeller shaft as well as the driving tubular and solid-shafts, rotating about the same aXis.

Having thus described my invention, what I claim as new and novel is j l i l. In a power transmission construction of the class described, a housing, apair of axle shafts supported therein, a standard differential mechanism including a driving disc having inner and outer concentric ring gears,

a propeller shaft associatedv with the front end of the housing, a solid driven inner pinion shaft disposed 'in alignment with said propeller shaft, a pair of longitudinally spaced bearing assemblies in which the opposite end portions of said solid shafts are Y mounted for rotation, a relatively large pinion gear fastened on said solid shaft and in driving mesh with the inner ring gear, a roller l; -aring structure mounted in said housing, an

Y outer tubular shaft surrounding and rotatable on said inner solid shaft, said tubular shaft having Yits front end mounted for rotation in said roller bearings, a relatively small pinion gear carried by the-tubular shaft and in mesh with the outer ring gear, an addiin the front end portion of the tubularfshaft, said solid shaft being mounted for rotation in said last-named bearing, said relatively large pinion gear having a recess defining a cavity,

and an end thrust bearing arranged in said cavity and receiving the rear end of said and outer shafts having independent driving teeth, a sliding collar splined for longitudinal sliding motion on said propeller shaft, operating means Vfor adjusting said collar, said' tubular shaft, the forward ends of the inner i collar being provided with inteinal and enternal driving teeth adapted to be selectively meshed with the driving teeth of either the inner solid shafts or the outer hollow shaft.

2. In a power transmission mechanism for a standard automobile, the combination vof a ,enternallt'eetm means to slide the sleeve into driving engagement with either set of teetii on the tubular or solid shaft, a tapered roller bearing fitting into the inner side of the forward opening of the differential housing, the

forward end of said tubular shaft being supported in said tapered roller bearing, a smaller tapered roller hearing fitted inside of the 'said tubular .shaft at its forward end and supporting said solid shaft, a projection on the rear end ofv said solid inner shaft, a tapered roller bearing on said pi'ogection, said Y tapered roller bearing having rollers and cones arranged to take the thrust of said solid inner shaft and to act as a complementary thrust bearing to the aforesaid taper vroller bearing inside the forward endof aforementioned tubular shaft its endl to carry the forward end of said inner solid shaft, the large pinion gearron said innerV .solid shaft having recessed from its forward surface a cavit to accommodate and carry a o tapered roller earing, a tapered roller bearing within said cavity and supporting the i rear end of said tubular shaft, said tapered Vrollerbearing having rollers so arranged as t0 take the thrust vof said tubular shaft and complementary to the aforementioned tapered roller bearing fitted tothe inner surface of the. forward opening in the bell-shaped housing..

In testimony whereof I afliX my signature.

JESSE C. SMOOT.

tional roller bearing structure mounted with- 

